About

CEM 3340 DIY MODULE
 
 

This is the beginning of a larger DIY HOW TO project, following on from my previous one regarding building a simple case and power supply.

This is the CORE of a VCO module made with a CEM3340 chip.

I intend to design add-ons (hence the large amount of spare space on the stripboard layout!)

They will appear on the patreon before they appear anywhere else! as i am going to get them all designed and put them all into 1 big video in a month or so! so if you want them as soon as i design them check here https://www.patreon.com/lookmumnocomputer   :)

including Squarewave sine wave, PWM, syncs, fm in, octave select etc.

heres the stripboard layout and schematic!

CEM 3340 Core Schematic Module. it only has 1 CV input, and 1course tune, however you can add more CV inputs if you want straight away, by simply adding another 100k resistor to a jack socket coming off pin 15 of the CEM3340!!!

The TL072 is there because if you plug some things straight out of the CEM 3340 it effects the tune and sometimes doesnt play at all, so thats there just to condition the output so your not effecting the module with whatever you plug the audio out into!

I ommited the High tuning tracking feature, as i felt it complicated things, it made sense for a proper synth, but realistically who is going to need bang on tuning over a 9 octave range?????? WHO???????????????? 

Heres the stripboard layout, easy as chips! all the space is there for later add ons which i will be working on this month.

LIST OF COMPONENTS REQUIRRRREEDDDDD :-

I will work on a shopping list in the coming days! but heres a list for now anyways! go on mouser/rapid electronics or something and just type these things into the search tab, lots of them come up, but usually they all do the same thing!

CEM 3340 Part List

- Stripboard a piece 46 x 24 dots

-Trimpot 10k any trimpot will do!

-100k potentiometer

-ic sockets one 8 leg and a 16 leg one

- 2  x   470R resistor,,, just a metal film resistor, but tbh! any will do!

-620R resistor,,, just a metal film resistor, but tbh! any will do!

-1K8 resistor,,, just a metal film resistor, but tbh! any will do!

-5K6 resistor,,, just a metal film resistor, but tbh! any will do!

-24K resistor,,, just a metal film resistor, but tbh! any will do!

-2  x  100Kresistor,,, just a metal film resistor, but tbh! any will do!

-1M5 resistor,,, just a metal film resistor, but tbh! any will do!

-1nf capacitor, i used ceramic, but meh whatever!

-10nf capacitor, same!

-CEM3340 its a little pricey, I havent tried it but there are cheap knockoffs! i will try them there is no reason why they wont work! but i may be wrong! its called the AS3340 ,,, thanks to Václav Pechman for bringing this to my attention.

(link to CEM3340 , https://www.thonk.co.uk/shop/curtis-cem3340-ic-vco-chip/  )

- TL072 , like i said this just conditions the output, however if you plan to wire the oscillator straight into a filter or something, you can try and skip this!!!!!!

-jack sockets

and allll that jazz1!!!